Template:Inflation/doc

This template calculates inflation based on several inflation index data sets. The template uses an identification code for an inflation index (usually a country code), an original value, an original start_year and either a specific reference end_year or by default the latest currently available end year,[1] and calculates the equivalent value from historical economic changes between the original and reference years. For example, this template calls the United States inflation table located in the sub-template Template:Inflation/US/dataset to perform the U.S. calculation.

Aside from a convenient way to calculate values from different specified time periods, this template allows a regularly automatically updated calculation of value based on the most recent available inflation data. Whenever inflation tables are updated, potentially annually, all articles using this template have their displayed values updated accordingly.

{{Inflation|index|value|start_year}}
{{Inflation|index|value|start_year|end_year}}
{{Inflation|index|value|start_year|r=decimals|fmt=c}}
{{Inflation|index|value|start_year|r=decimals|fmt=eq}}
{{Inflation|index|value|start_year|r=decimals|fmt=eq|cursign=X}}

The supported countries are listed below, with their index and available data periods:

index Country start_year minimum end_year maximum
AU Australia[2] 1901 2018
AU-road Australia [...?][3] 1998 2018
BD Bangladesh[4] 1986 2014
CA Canada[5] 1688 2020
DE Germany[6] 1882 2017
IN India[7] 1595 2019
JP Japan[8] 1946 2019
PH Philippines[9] 1985 2019
PK Pakistan[10] 1960 2019
UK United Kingdom[11] 1209 2019
UK-GDP United Kingdom GDP deflator[12] 1700 2019
US United States[13] 1800 2021
US-GDP United States GDP deflator[14] 1790 2020
ZAR South Africa[15] 1960 2018
KRW South Korea[16] 1951 2017

Parameters

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  • |index= (parameter 1), required, an index code for one of several available inflation indexes.
  • |value= (parameter 2), required, original price or value from which to base the inflation calculation on. Will ignore any commas, but must not have a currency symbol.
  • |start_year= (parameter 3), required, original year from which to base the inflation calculation on. Must be a year available in the chosen inflation index. As an exception to this, if the current year is specified and no end_year is specified, the template will output value unchanged, as it can be assumed an inflation of zero.
  • |end_year= (parameter 4), optional, reference year for which to calculate inflation. Must be higher (later) than start_year, but not higher than the highest (most recent) year available in the chosen inflation index, and will default to the highest (most recent) available year if omitted.
  • |r=digit sets the digits to which the value must be rounded. A negative value indicates rounding to an upper significant digit, and a positive value indicates a fractional digit including trailing zeros. Defaults to 0, i.e., without cents.
  • |fmt=c will insert thousands separator commas into the calculated value.
  • |fmt=eq will show an equivalent-to phrase, in the format, "equivalent to cursignend_value in end_year". Uses thousands separator commas.
    • |cursign= will set the currency symbol to be shown. Only functions when |fmt=eq is used. Can use advanced symbol formats, but can only precede the calculated value. Default is $.

Examples

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  • Green tickY {{Inflation|DE|100|2000}}65
  • Green tickY {{Inflation|US|595|1982}}1671
  • Green tickY {{Inflation|US|595|1982|fmt=eq}}equivalent to $1,671 in 2021
  • Green tickY {{Inflation|US|800|1942|fmt=eq|r=-3}}equivalent to $13,000 in 2021
  • Green tickY {{Inflation|US|100|2010|2012|fmt=eq|r=2}}equivalent to $105.28 in 2012
  • Green tickY US$595 ({{Inflation|US|595|1982|fmt=eq}})US$595 (equivalent to $1,671 in 2021)
  • Green tickY US$595 ({{Inflation|US|595|1982|fmt=eq|cursign=[[United States dollar|US$]]}})US$595 (equivalent to US$1,671 in 2021)
  • Green tickY $21 million (equivalent to ${{Inflation|US|21|2005|r=2}} million in {{Inflation/year|US}})$21 million (equivalent to $29.14 million in 2021)
  • Red XN {{Inflation|UK|1|1209|fmt=eq}}equivalent to $1,419 in 2019 (Wrong currency symbol)
  • Green tickY {{Inflation|UK|1|1209|fmt=eq|cursign=£}}equivalent to £1,419 in 2019
  • Green tickY {{Inflation|AU|100|2024|fmt=eq}}equivalent to $100 in 2024
  • Green tickY ${{Inflation|US|100|2024}} in {{Inflation/year|US}}$100 in 2021

It is possible to use the template in incorrect ways without producing error messages. Please read the warnings and appropriate uses of this template at the beginning of the template description.

  • Red XN $595 (${{Inflation|US|595|1982|fmt=c}} today)$595 ($1,671 today) (Misleading time reference)
  • Red XN $595 (${{Inflation|US|595|1982|fmt=c}} in {{CURRENTYEAR}})$595 ($1,671 in 2024) (Misleading time reference)
  • Red XN $100 (${{Inflation|US|595|1982|fmt=c}} adjusted for inflation)$100 ($1,671 adjusted for inflation) (Misleading time reference)
  • Green tickY $595 ({{Inflation|US|595|1982|fmt=eq}})$595 (equivalent to $1,671 in 2021)
  • Green tickY $595 (equivalent to ${{Inflation|US|595|1982|fmt=c}} in {{Inflation/year|US}})$595 (equivalent to $1,671 in 2021)
  • Red XN Jane Doe amassed a fortune of $1 billion in 1975, making her worth ${{Inflation|US|1|1975|fmt=c}} billion in {{Inflation/year|US}}.Jane Doe amassed a fortune of $1 billion in 1975, making her worth $5 billion in 2021. (CPI is not for personal wealth of the wealthy – use GDP deflator instead)
  • Red XN Jane Doe amassed a fortune of $1 billion in 1975, equivalent to ${{Inflation|US|1|1975|fmt=c}} billion in {{Inflation/year|US}}.Jane Doe amassed a fortune of $1 billion in 1975, equivalent to $5 billion in 2021. (CPI is not for personal wealth of the wealthy – use GDP deflator instead)
  • Green tickY Jane Doe amassed a fortune of $1 billion in 1975, equivalent to ${{Inflation|US-GDP|1|1975|fmt=c}} billion in {{Inflation/year|US-GDP}}.Jane Doe amassed a fortune of $1 billion in 1975, equivalent to $4 billion in 2020

Entering invalid parameters or omitting required parameters will result in an error message and categorization into Category:Pages with errors in inflation template.

  • Red XN {{Inflation}}Error when using {{Inflation}}: |index= (parameter 1), |value= (parameter 2) and |start_year= (parameter 3) must be specified.
  • Red XN {{Inflation|abc}}Error when using {{Inflation}}: |value= (parameter 2) and |start_year= (parameter 3) must be specified.
  • Red XN {{Inflation|AU}}Error when using {{Inflation}}: |value= (parameter 2) and |start_year= (parameter 3) must be specified.
  • Red XN {{Inflation|AU|100}}Error when using {{Inflation}}: |start_year= (parameter 3) must be specified.
  • Red XN {{Inflation|abc|€100|1980}}Error when using {{Inflation}}: |index=abc (parameter 1) not a recognized index.
  • Red XN {{Inflation|DE|€100|1980}}Error when using {{Inflation}}: NaN, check parameters for non-numeric data: |value=€100 (parameter 2).
  • Red XN {{Inflation|DE|€100|zzzz|zzzz|r=zzzz}}Error when using {{Inflation}}: NaN, check parameters for non-numeric data: |value=€100 (parameter 2), |start_year=zzzz (parameter 3), |end_year=zzzz (parameter 4) and |r=zzzz.
  • Red XN {{Inflation|AU|100|1200|2025}}Error when using {{Inflation}}: |start_year=1200 (parameter 3) is lower than the earliest available year (1901) in index "AU" and |end_year=2025 (parameter 4) is greater than the latest available year (2018) in index "AU".
  • Red XN {{Inflation|AU|100|2005|2004}}Error when using {{Inflation}}: |start_year=2005 (parameter 3) is greater than |end_year=2004 (parameter 4).
  • Red XN {{Inflation|AU|100|2005|2025|fmt=eq}}Error when using {{Inflation}}: |end_year=2025 (parameter 4) is greater than the latest available year (2018) in index "AU".
  • Red XN {{Inflation|AU|100|2024|2025|fmt=eq}}Error when using {{Inflation}}: |end_year=2025 (parameter 4) is greater than the latest available year (2018) in index "AU".
  • Red XN {{Inflation|AU|100|2024|1905|fmt=eq}}Error when using {{Inflation}}: |start_year=2024 (parameter 3) is greater than |end_year=1905 (parameter 4).
  • Red XN {{Inflation|AU|100|2025|fmt=eq}}Error when using {{Inflation}}: |start_year=2025 (parameter 3) is greater than the latest available year (2018) in index "AU".

Tips & tricks

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Currency conversion

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This template is currency agnostic, which means it doesn't convert between different currencies. Thus, if you wanted to know how much DM 1,000.00 marks in 1960 are worth nowadays, entering {{Inflation|DE|1000|1960|r=2}} would provide a result (2255.66) still in marks, not in euros.

Consequently, if you need a result in another currency than the one in which the original value is stated, for now you must do the conversion manually, as in the following example which uses the defined conversion rate of € 1 = DM 1.95583:

  • Green tickY {{#expr:({{Inflation|DE|1000|1960|r=2}} / 1.95583) round 2}}1153.3

 ToDo A currency conversion template to ease these conversion tasks is planned. This section will be updated accordingly once it's developed.

Rounding

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By default the values are calculated to the unit, as for all but very low values cents are undesirable. You can specify rounding with the |r= parameter which determines the number of decimals. To obtain cents use |r=2, but other values can be used, including negative ones: |r=-3, for example, will round to the nearest thousand, |r=-6 to the nearest million, and so on. It is advisable to avoid excessive precision; even if the start value is known to be exact, the template's result will not be because the inflation index tables are rarely accurate to more than about 1%, and a granularity of whole years is used.

Very large results

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Very large results are expressed in scientific notation ("1.2E+14" instead of "120000000000000") which is normally not desirable. A workaround is to express the value to be inflated with fewer digits, adding a multiplier text such as "trillion" after the result, using the "Show preview" button as many times as needed, changing parameters until the best result is found:

  • Green tickY ${{Inflation|US-GDP|1000000000000|1900|r=-11|fmt=c}}$26,200,000,000,000
  • Red XN ${{Inflation|US-GDP|10000000000000|1900|r=-12|fmt=c}}$262,000,000,000,000
  • Red XN ${{Inflation|US-GDP|10000000000|1900|r=-9|fmt=c}} thousand$262,000,000,000 thousand
  • Green tickY ${{Inflation|US-GDP|10000000|1900|r=-6|fmt=c}} million$262,000,000 million
  • Green tickY ${{Inflation|US-GDP|10000|1900|r=-3|fmt=c}} billion$262,000 billion
  • Green tickY ${{Inflation|US-GDP|10|1900|fmt=c}} trillion$262 trillion

The following section provides an automated way of avoiding this trial and error scenario.

Format price

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{{Format price}} is a template specifically designed to display price values, both big and small, in a readable way. For example, instead of showing the whole of a huge number such as "953,783,409,856.12", it would show it as "954 billion", while small numbers have their cents part appearing as expected, "1234.5" being properly shown as "1.23 thousand".

  • Green tickY ${{Format price|{{Inflation|US-GDP|10000000000000|1900}}}}$262 trillion
  • Green tickY ${{Format price|{{Inflation|US-GDP|1000000|1990}}}}$1.79 million
  • Green tickY DM {{Format price|{{Inflation|DE|1000000|1957|1978}}}}DM 2.01 million
  • Green tickY £{{Format price|{{Inflation|UK-GDP|1000|1323}}}}£662 thousand

Documenting

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It's a good practice to provide a valid reference for the prices calculated with this template in articles where it's used. The template {{Inflation/fn}} was developed to ease this task. It accepts as its single parameter the same country codes used here, and will generate one or more appropriate footnotes. Typically, this is how a piece of text using it looks like:

  • In 1985 a unit cost on average $1,040. This is {{Inflation|US|1040|1985|fmt=eq}}}}.{{Inflation/fn|US}}

Resulting in this converted code (notice the footnote link at the end):

  • In 1985 a unit cost on average $1,040. This is equivalent to $2,620 in 2021.[13]

The footnote thus generated appears whenever {{reflist}} or <references /> is used in an article, usually in its "References" section. See below for the live example in this document's own References section, or click the above generated footnote to jump to it.

Limitations

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  1. Currently it isn't possible to "de-inflate" a value to what it would have been in a previous year. If you need this functionality, please request it at the talk page. Adding it won't be difficult, but there's no point in doing so before someone actually needs it.
  2. Substitution isn't supported at all. Trying to {{subst:Inflation|...}} would only result in a long sequence of embedded parser code without any direct benefit. If you need to obtain an inflated price only once, please use the special ExpandTemplates page then copy the result and paste it at the desired location.

Developer documentation

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An inflation series represents templates in the following categories:

  • Template:Inflation/index
  • Template:Inflation/index/dataset
  • Template:Inflation/index/startyear
  • Template:Inflation/doc/index (Which is then displayed at Inflation/name/dataset as the documentation, and needs to refer to the original data source)

Modifications need to be made to:

Current subpages:

Pages with the prefix 'Inflation' in the 'Template' and 'Template talk' namespaces:

Template:
Inflation
Template talk:

TemplateData

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This is the TemplateData for this template used by TemplateWizard, VisualEditor and other tools. See a monthly parameter usage report for Template:Inflation in articles based on its TemplateData.

TemplateData for Inflation

This template calculates inflation based on several inflation index data sets. Note that this template defaults to calculating the inflation of Consumer Price Index values: staples, workers' rent, small service bills (doctor's costs, train tickets). For inflating capital expenses, government expenses, or the personal wealth and expenditure of the rich, the US-GDP or UK-GDP indexes should be used, which calculate inflation based on the [[gross domestic product]] (GDP) for the [[United States]] and [[United Kingdom]], respectively.

Template parameters

This template prefers inline formatting of parameters.

ParameterDescriptionTypeStatus
Indexindex 1

An index code for one of several available inflation indexes. One of AU, AU-road, BD, CA, DE, IN, JP, PH, PK, UK, UK-GDP, US, US-GDP, ZAR.

Example
US
Stringrequired
Valuevalue 2

Original price or value from which to base the inflation calculation on. Will ignore any commas.

Example
1000
Numberrequired
Start yearstart_year 3

Original year from which to base the inflation calculation on. Must be a year available in the chosen inflation index. As an exception to this, if the current year is specified and no 'End year' is specified, the template will output value unchanged, as it can be assumed an inflation of zero.

Example
1975
Numberrequired
End yearend_year 4

Reference year for which to calculate inflation. Must be higher (later) than 'Start year', but not higher than the highest (most recent) year available in the chosen inflation index, and will default to the highest (most recent) available year if omitted.

Example
2015
Numberoptional
Number of digitsr

Sets the digits to which the value must be rounded. A negative value indicates rounding to an upper significant digit, and a positive value indicates a fractional digit including trailing zeros. Defaults to 0.

Default
0
Example
1
Numberoptional
Formatfmt

"c" will insert thousands separator commas into the calculated value. "eq" will show an equivalent-to phrase, in the format, "equivalent to (cursign)(end_value) in (end_year)". Uses thousands separator commas.

Example
eq
Stringoptional
Currency signcursign

Sets the currency symbol to be shown. Only functions when Format "eq" is used. Can use advanced symbol formats, but can only precede the calculated value. Default is $.

Default
$
Example
Stringoptional

See also

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References

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  1. How recently depends on how the data set for each country is constructed, and on the internal tables being updated accordingly every January. Some data tables provide inflation data up to December 31, 2023, others up to roughly June-July 2023, and others yet up to December 31, 2022.
  2. Australian Consumer Price Inflation figures follow the Long Term Linked Series provided in Australian Bureau of Statistics (2011) 6461.0 – Consumer Price Index: Concepts, Sources and Methods, 2011 as explained at §§3.10–3.11; this series comprises "from 1901 to 1914, the A Series Retail Price Index; from 1914 to 1946–47, the C Series Retail Price Index; from 1946–47 to 1948–49, a combination of the C Series Index, excluding rent, and the housing group of the CPI; and from 1948–49 onwards, the CPI." (3.10). Retrieved May 4, 2015
  3. Inflated values automatically calculated using the "3101 Road and bridge construction Australia" series provided in Australian Bureau of Statistics (2014) 6427.0 – Producer Price Indexes, Australia, Mar 2014: Table 17 Output of the Construction industries, subdivision and class index numbers. Retrieved 14 June 2014.
  4. Bangladesh – Consumer price index, International Monetary Fund, International Financial Statistics and data files.[dubious ]
  5. Canadian inflation numbers based on Statistics Canada. "Consumer Price Index, historical summary". Statistics Canada. Retrieved April 26, 2018. CANSIM, table (for fee) 326-0021 and Catalogue nos. 62-001-X, 62-010-X and 62-557-X. And "Consumer Price Index, by province (monthly) (Canada)". Statistics Canada. Retrieved April 26, 2018.
  6. German inflation numbers based on data available from Deutsches Statistisches Bundesamt.
  7. Historic inflation India – CPI inflation, Inflation.eu, retrieved 24 January 2017
  8. Japanese Historical Consumer Price Index numbers based on data available from the Japanese Statistics Bureau. Japan Historical Consumer Price Index (CPI) – 1970 to 2014 Retrieved 30 July 2014. For between 1946 and 1970, from "昭和戦後史". Retrieved 2015-01-24.
  9. Consumer Price Index,Inflation Rate and Purchasing Power of the Peso (national averages)
  10. Pakistan – Consumer price index, International Monetary Fund, International Financial Statistics and data files.[dubious ]
  11. UK Retail Price Index inflation figures are based on data from Clark, Gregory (2017). "The Annual RPI and Average Earnings for Britain, 1209 to Present (New Series)". MeasuringWorth. Retrieved January 27, 2019.
  12. United Kingdom Gross Domestic Product deflator figures follow the Measuring Worth "consistent series" supplied in Thomas, Ryland; Williamson, Samuel H. (2018). "What Was the U.K. GDP Then?". MeasuringWorth. Retrieved January 5, 2018.
  13. 13.0 13.1 Federal Reserve Bank of Minneapolis Community Development Project. "Consumer Price Index (estimate) 1800–". Federal Reserve Bank of Minneapolis. Retrieved January 2, 2019.
  14. Thomas, Ryland; Williamson, Samuel H. (2018). "What Was the U.S. GDP Then?". MeasuringWorth. Retrieved January 5, 2018. United States Gross Domestic Product deflator figures follow the Measuring Worth series.
  15. South Africa – Consumer price index, International Monetary Fund, International Financial Statistics and data files.[dubious ]
  16. Consumer Price index from Statistics Korea. Consumer Price Index by year. Retrieved 3 April 2018